Numerical simulations of rotating Rayleigh-Bénard convection

The Rayleigh-Bénard (RB) system is relevant to astro- and geophysical phenomena, including convection in the ocean, the Earth’s outer core, and the outer layer of the Sun. The dimensionless heat transfer (the Nusselt number Nu) in the system depends on the Rayleigh number Ra=ßg¿L 3/(¿¿) and the Prandtl number Pr=¿/¿. Here, ß is the thermal expansion coefficient, g the gravitational acceleration, ¿ the temperature difference between the bottom and top, and ¿ and ¿ the kinematic viscosity and the thermal diffusivity, respectively. The rotation rate H is used in the form of the Rossby number Ro=(ßg¿/L)/(2H). The key question is: How does the heat transfer depend on rotation and the other two control parameters: Nu(Ra, Pr, Ro)? Here we will answer this question by giving a summary of our result

On the multiplicity of the O-star Cyg OB2 #8A and its contribution to the gamma-ray source 3EG J2033+4118

We present the results of an intensive spectroscopic campaign in the optical waveband revealing that Cyg OB2 #8A is an O6 + O5.5 binary system with a period of about 21.9 d. Cyg OB2 #8A is a bright X-ray source, as well as a non-thermal radio emitter. We discuss the binarity of this star in the framework of a campaign devoted to the study of non-thermal emitters, from the radio waveband to gamma-rays. In this context, we attribute the non-thermal radio emission from this star to a population of relativistic electrons, accelerated by the shock of the wind-wind collision. These relativistic electrons could also be responsible for a putative gamma-ray emission through inverse Compton scattering of photospheric UV photons, thus contributing to the yet unidentified EGRET source 3EG J2033+4118.Comment: 8 pages, 4 figures, conference on "The Multiwavelength Approach to Gamma-Ray Sources", to appear in Ap&S

Childhood Trauma and COMT Genotype Interact to Increase Hippocampal Activation in Resilient Individuals

Both childhood trauma and a functional COMT genetic polymorphism have been associated with PTSD and depression; however, it is still unclear whether the two interact and how this interaction relates to long-term risk or resilience. Imaging and genotype data were collected on 73 highly traumatized women. DNA extracted from saliva was used to determine COMT genotype (Val/Val, n=38, Met carriers, n=35). Functional MRI data were collected during a Go/NoGo task to investigate the neurocircuitry underlying response inhibition. Self-report measures of adult and childhood trauma exposure, PTSD and depression symptom severity, and resilience were collected. Childhood trauma was found to interact with COMT genotype to impact inhibition-related hippocampal activation. In Met carriers, more childhood trauma was associated with decreased hippocampal activation, whereas in the Val/Val group childhood trauma was related to increased hippocampal activation. Second, hippocampal activation correlated negatively with PTSD and depression symptoms, and positively with trait resilience. Moreover, hippocampal activation mediated the relationship between childhood trauma and psychiatric risk or resilience in the Val/Val, but not in the Met-carrier group. These data reveal a potential mechanism by which childhood trauma and COMT genotype interact to increase risk for trauma-related psychopathology or resilience. Hippocampal recruitment during inhibition may improve the ability to use contextual information to guide behavior, thereby enhancing resilience in trauma-exposed individuals. This finding may contribute to early identification of individuals at risk, and suggests a mechanism that can be targeted in future studies aiming to prevent or limit negative outcomes

Ultrafast photoinduced reflectivity transients in (Nd0.5Sr0.5)MnO3(Nd_{0.5}Sr_{0.5})MnO_3

The temperature dependence of ultrafast photoinduced reflectivity transients is reported in Nd$_{0.5}$Sr$_{0.5}$MnO$_{3}$ thin film. The photoinduced reflectivity shows a complex response with very different temperature dependences on different timescales. The response on the sub-ps timescale appears to be only weakly sensitive to the 270K-metal-insulator phase transition. Below $\sim 160$ K the sub-ps response displays a two component behavior indicating inhomogeneity of the film resulting from the substrate induced strain. On the other hand, the slower response on the 10-100 ps timescale is sensitive only to the metal-insulator phase transition and is in agreement with some previously published results. The difference in the temperature dependences of the responses on nanosecond and $\mu$s timescales indicates that thermal equilibrium between the different degrees of fredom is established relatively slowly - on a nanosecond timescale

A systematic review of the quality and scope of economic evaluations in child oral health research

Background Economic evaluations provide policy makers with information to facilitate efficient resource allocation. To date, the quality and scope of economic evaluations in the field of child oral health has not been evaluated. Furthermore, whilst the involvement of children in research has been actively encouraged in recent years, the success of this movement in dental health economics has not yet been explored. This review aimed to determine the quality and scope of published economic evaluations applied to children’s oral health and to consider the extent of children’s involvement. Methods The following databases were searched: CINAHL, Cochrane Library, Econlit, EThOS, MEDLINE, NHS EED, OpenGrey, Scopus, Web of Science. Full economic evaluations, relating to any aspect of child oral health, published after 1997 were included and appraised against the Drummond checklist and the Consolidated Health Economic Evaluation Reporting Standards by a team of four calibrated reviewers. Data were also extracted regarding children’s involvement and the outcome measures used. Results Two thousand seven hundred fifteen studies were identified, of which 46 met the inclusion criteria. The majority (n = 38, 82%) were cost-effectiveness studies, with most focusing on the prevention or management of dental caries (n = 42, 91%). One study quantified outcomes in Quality Adjusted Life Years (QALYs), and one study utilised a child-reported outcome measure. The mean percentage of applicable Drummond checklist criteria met by the studies in this review was 48% (median = 50%, range = 0–100%) with key methodological weaknesses noted in relation to discounting of costs and outcomes. The mean percentage of applicable CHEERS criteria met by each study was 77% (median = 83%, range = 33–100%), with limited reporting of conflicts of interest. Children’s engagement was largely overlooked. Conclusions There is a paucity of high-quality economic evaluations in the field of child oral health. This deficiency could be addressed through the endorsement of standardised economic evaluation guidelines by dental journals. The development of a child-centred utility measure for use in paediatric oral health would enable researchers to quantify outcomes in terms of quality adjusted life years (QALYs) whilst promoting child-centred research

High frequency of inactivating tetraspanin CD37 mutations in diffuse large B-cell lymphoma at immune-privileged sites

Item does not contain fulltex

Female sex is a risk factor for painful diabetic peripheral neuropathy: the EURODIAB prospective diabetes complications study

Aims/hypothesis While the risk factors for diabetic peripheral neuropathy (DPN) are now well recognised, the risk factors for painful DPN remain unknown. We performed analysis of the EURODIAB Prospective Complications Study data to elucidate the incidence and risk factors of painful DPN. Methods The EURODIAB Prospective Complications Study recruited 3250 participants with type 1 diabetes who were followed up for 7.3±0.6 (mean ± SD) years. To evaluate DPN, a standardised protocol was used, including clinical assessment, quantitative sensory testing and autonomic function tests. Painful DPN (defined as painful neuropathic symptoms in the legs in participants with confirmed DPN) was assessed at baseline and follow-up. Results At baseline, 234 (25.2%) out of 927 participants with DPN had painful DPN. At follow-up, incident DPN developed in 276 (23.5%) of 1172 participants. Of these, 41 (14.9%) had incident painful DPN. Most of the participants who developed incident painful DPN were female (73% vs 48% painless DPN p=0.003) and this remained significant after adjustment for duration of diabetes and HbA1c (OR 2.69 [95% CI 1.41, 6.23], p=0.004). The proportion of participants with macro- or microalbuminuria was lower in those with painful DPN compared with painless DPN (15% vs 34%, p=0.02), and this association remained after adjusting for HbA1c, diabetes duration and sex (p=0.03). Conclusions/interpretation In this first prospective study to investigate the risk factors for painful DPN, we definitively demonstrate that female sex is a risk factor for painful DPN. Additionally, there is less evidence of diabetic nephropathy in incident painful, compared with painless, DPN. Thus, painful DPN is not driven by cardiometabolic factors traditionally associated with microvascular disease. Sex differences may therefore play an important role in the pathophysiology of neuropathic pain in diabetes. Future studies need to look at psychosocial, genetic and other factors in the development of painful DPN

Simulations of the Static Friction Due to Adsorbed Molecules

The static friction between crystalline surfaces separated by a molecularly thin layer of adsorbed molecules is calculated using molecular dynamics simulations. These molecules naturally lead to a finite static friction that is consistent with macroscopic friction laws. Crystalline alignment, sliding direction, and the number of adsorbed molecules are not controlled in most experiments and are shown to have little effect on the friction. Temperature, molecular geometry and interaction potentials can have larger effects on friction. The observed trends in friction can be understood in terms of a simple hard sphere model.Comment: 13 pages, 13 figure

Episodic memory after trauma exposure: Medial temporal lobe function is positively related to re-experiencing and inversely related to negative affect symptoms

Hippocampal structure is particularly sensitive to trauma and other stressors. However, previous findings linking hippocampal function with trauma-related psychopathology have been mixed. Heterogeneity in psychological responses to trauma has not been considered with respect to hippocampal function and may contribute to mixed findings. To address these issues, we examined associations between data-driven symptom dimensions and episodic memory formation, a key function of the hippocampus, in a trauma-exposed sample. Symptom dimensions were defined using principal components analysis (PCA) in 3881 trauma-exposed African-American women recruited from primary care waiting rooms of a large urban hospital. Hippocampal and amygdala function were subsequently investigated in an fMRI study of episodic memory formation in a subset of 54 women. Participants viewed scenes with neutral, negative, and positive content during fMRI, and completed a delayed cued recall task. PCA analysis produced five symptom dimensions interpreted as reflecting negative affect, somatic symptoms, re-experiencing, hyper-arousal, and numbing. Re-experiencing was the only symptom type associated with hippocampal function, predicting increased memory encoding-related activation in the hippocampus as well as the amygdala. In contrast, the negative affect component predicted lower amygdala activation for subsequently recalled scenes, and lower functional coupling with other important memory-related regions including the precuneus, inferior frontal gyrus, and occipital cortex. Symptom dimensions were not related to hippocampal volume. The fMRI findings for re-experiencing versus negative affect parallel differences in behavioral memory phenomena in PTSD versus MDD, and highlight a need for more complex models of trauma-related pathology